Haemophilus influenzae is the cause of several serious human diseases, such as meningitis, epiglottitis, septicemia and otitis media. There are six serotypes of H. influenzae, designated a to f, that are identified by their capsular polysaccharide. H. influenzae type b (Hib) was a major cause of bacterial meningitis until the introduction of several Hib conjugate vaccines in the 1980's (ref. 1. Throughout this application, various references are referred to in parenthesis to more fully describe the state of the art to which this invention pertains. Full bibliographic information for each citation is found at the end of the specification, immediately preceding the claims. The disclosures of these references are hereby incorporated by reference into the present disclosure). Vaccines based upon H. influenzae type b capsular polysaccharide conjugated to diphtheria toxoid (ref. 2), tetanus toxoid (ref. 3 and U.S. Pat. No. 4,496,538), or Neisseria meningitidis outer membrane protein (ref. 4) have been effective in reducing H. influenzae type b-induced meningitis. The other serotypes of H. influenzae are associated with invasive disease at low frequencies, although there appears to be an increase in the incidence of disease caused by these strains as the incidence of Hib disease declines (refs. 5, 6). Non-encapsulated or non-typeable H. influenzae (NTHi) are also responsible for a wide range of human diseases including otitis media, epiglottitis, pneumonia and tracheobronchitis. The incidence of NTHi-induced disease has not been affected by the introduction of the Hib vaccines (ref. 7).
Otitis media is the most common illness of early childhood, with 60 to 70% of all children, of less than 2 years of age, experiencing between one and three ear infections (ref. 8). Chronic otitis media is responsible for hearing, speech and cognitive impairments in children. H. influenzae infections account for about 30% of the cases of acute otitis media and about 60% of chronic otitis media. In the United States alone, treatment of otitis media costs between 1 and 2 billion dollars per year for antibiotics and surgical procedures, such as tonsillectomies, adenoidectomies and insertion of tympanostomy tubes. It is estimated that an additional $30 billion is spent per annum on adjunct therapies, such as speech therapy and special education classes. Furthermore, many of the causative organisms of otitis media are becoming resistant to antibiotic treatment. An effective prophylactic vaccine against otitis media is thus desirable.
During natural infection by NTHi, surface-exposed outer membrane proteins that stimulate an antibody response are potentially important targets for bactericidal and/or protective antibodies and therefore potential vaccine candidates. Barenkamp and Bodor (ref. 9) demonstrated that convalescent sera from children suffering from otitis media due to NTHi, contained antibodies to high molecular weight (HMW) proteins. About 70 to 75% of NTHi strains express the HMW proteins and most of these strains contain two gene clusters termed hmw1ABC and hmw2ABC (refs. 10, 11). The HMWA proteins have been demonstrated to be adhesins mediating attachment to human epithelial cells (ref. 12). Immunization with a mixture of native HMW1A and HMW2A proteins resulted in partial protection in the chinchilla intrabulla challenge model of otitis media (ref. 13).
U.S. Pat. No. 5,603,938 (Barenkamp), assigned to St. Louis University and Washington University and the disclosure of which is incorporated herein by reference, describes the cloning, expression and sequencing of the genes encoding the HMW1 and HMW2 proteins from strain 12 of non-typeable Haemophilus. The HMW proteins are a family of proteins from non-typeable Haemophilus of molecular weight of about 120 to 125 kDa which are found in non-typeable Haemophilus strains. The HMW proteins are absent from encapsulated strains of Haemophilus. 
The production of native HMW proteins from H. influenzae strains is very low and a method for producing protective recombinant HMW (rHMW) proteins has been described in copending U.S. patent application Ser. No. 09/167,568 filed Oct. 7, 1998, assigned to the assignee hereof and the disclosure of which is incorporated herein by reference. A chinchilla nasopharyngeal colonization model has been developed specifically to demonstrate vaccine efficacy of adhesins (ref. 14) and the rHMW proteins are protective in this model as described in the aforementioned copending U.S. patent application Ser. No. 09/167,568. The rHMW1A and rHMW2A proteins were shown to afford equivalent protection to each other and the rHMW1A protein was chosen for further vaccine studies. In this application, rHMW refers to the recombinant HMW1A proteins from NTHi strain 12, although the corresponding recombinant HMW1A protein from other NTHi strains and the corresponding rHMW2A protein from NTHi strains may be employed for the rHMW. The corresponding naturally-occurring proteins may be employed.
When under environmental stress, such as high temperature, organisms overproduce stress response or heat shock proteins (hsps). Bacterial hsps have been shown to be important immunogens, stimulating both B cells and T cells (ref. 16). The bacterial HtrA or DegP heat shock proteins are expressed under conditions of stress and the H. influenzae HtrA protein has been shown to be a partially protective antigen in the intrabulla challenge model of otitis media (ref. 17). The HtrA proteins are serine proteases and their proteolytic activity makes them unstable. In addition, as components of a multicomponent vaccine, the wild-type HtrA protein will degrade admixed antigens. The site-directed mutagenesis of the H. influenzae htrA gene (termed hin47) and the properties of the mutants have been fully described in U.S. Pat. No. 5,506,139 (Loosmore et al), assigned to the Assignee hereof and the disclosure of which is incorporated herein by reference. The non-proteolytic HtrA analogue, H91A Hin47, has been shown to be a protective antigen against bacteremia caused by H. influenzae type b and against otitis media caused by non-typeable H. influenzae (ref. 17). Such analog is used herein, although any other non-proteolytic analog of Hin47 may be employed. HtrA was found in all strains examined, including all encapsulated strains of H. influenzae. 
Although the main goal of a prophylactic vaccine against H. influenzae disease, including otitis media, is to prevent the establishment of nasopharyngeal colonization by including an adhesin as immunogen, the HMW proteins are not present in encapsulated H. influenzae or in about 25% of NTHi strains. Therefore, a combination vaccine comprised of at least one adhesin molecule and an additional protective antigen found in all H. influenzae strains, will provide better coverage against disease and a broad spectrum of disease protection.
It would be desirable to provide efficacious combination vaccines comprising H. influenzae components containing selected relative amounts of selected antigens.